Process of producing solid drawn tubes.



No. 831,031. PATENTED SEPT. 18, 1906.

' E. BIER & A. HOFFMANN.

PROCESS OF PRODUCING SOLID DRAWN TUBES.

APPLICATION FILED DBO.2Z,1905.

2 SHBETSSHEET 1 No. 831,031. 'PATENTED SEPT. 18, 1906. E..BIER & A.HOFFMANN.

PROCESS OF PRODUGINGjSOL I D DRAWN TUBES.

APPLICATION FILED DBO.22,1905.

2 SHEBTS-SHEET 2:

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UNITED STATES PATENT OFFICE.

EMIL BIER, OF MI ILHEIM-ON-THE-RUHR, AND ADOLF HOFFMANN, OF COLOGNE,GERMANY.

Specification of Letters Patent.

Patented Sept. 18, 1906.

Application filed December 22,1905. Serial No. 292,987.

To all whom it mayconcern:

Be it known that we, EMIL BIER, residing at Miilheir'n-on-the-Ruhr, andADoLF HOFF- MANN, residing at Cologne, in the Province of the Rhine, Kindom of Prussia, German Empire, subjects 0 the King of Prussia, GermanEmperor, have invented a new and useful Process for Producing SolidDrawn Tubes, of which the following is a specification.

The processes hitherto in use for the preparation of hollow blocks suchas are used in industry especially for the purpose of rolling out and inthe construction of seamless tubes and boiler-making are verycomplicated and costly. In general this operation has hitherto beeneffected by removing by mechanical means the up or end of the castblock, which contains airoles and flaws after it has cooled, then againheatin the block and driving the mandrel throng it by means of a press.

The ,new process for the production of solid annular cast blocks dependsin principle on the circumstance that the material cast in a mold taering upward receives from its lower annufar surface an upwardlydirectedpressure and is moved upwardly, while at the same time a taperingmandrel in the interior of the block, though compelled to follow theupward motion, receives a pressure from above in the direction opp0-.site to the pressure acting upon the lower an nular surface of the blockwhich imparts to it a retrograde motionthat is to say, while the blockis pressed up in the tapering mold for a certain height the mandrelrises to a lesser height. By this means the following advantage isobtained: The pressure exercised by the tapering wall of the mold uponthe material while being raised compresses the latter to a high degreeof density, and being transferred also upon the mandrel this latter iscaused by friction to participate in the upward motion of the material.The shrinkin of the block would lead to a s litof t e same; but this isprevente by the retro rade motion caused, as stated, by a pressure cmabove upon the mandrel. This motion is regulated specially in eachparticular case according to the strength of the block and itsshrinking, so as to prevent any splitting of the cooling block.

Figure 1 of the accompanying drawmgs illustrates by way of example,partly in elevation and partly in section, a press which can be utilizedfor the carrying out of the process above set forth. Fig. 2 is a similarview showing the parts in elevated position. Fig. 3 is a diagramillustrating, respectively, the risin motlons of the metal block and ofthe man rel, the curves indicating how much the latter is graduallyfalling back.

In the drawings, a denotes the lower piston; b, the upper piston ;'c,the mold tapering upward, with a cylindrical part of the her ht d at itslower end. In the interior of t e mold there is placed thetapering-mandrel e, which is seated upon a thin sheetmetal disk f ofexactly the same diameter as the cylindrical part of the mold. A loosepiston 1 above piston a, filling this cylindrical part, is recessed atits upper face and counterbored centrally to receive the lower tenon' ofthe mandrel. By this means a closure against the material 9 is providedwhen it is poured in from above, and the retrograde motion h is assured,as the mandrel can recede into the recess of iston Z by shearing off themiddle part of disk The mold c rests upon a ring z and this in turn upona carriage k, which latter holds the piston Z, supportlng the disk f.

The press is shown in its initial position in the illustration, Fig. 1.The material 9 has been poured. The piston 12 has been lowered, togetherwith a plate m, upon the taperin mandrel e. As soon as the liquidmateria commences to harden hydraulic pressure is a plied to both thepistons a and 6 through t e tubes n and 0, whereby the following effectis attained: The lower piston a reaches the piston Z and carries itupward. This latter presses by means of its annular upper part upon thedisk f, which conveys the pressure to the material in the mold. The uper piston b acts upon the tapering mandrel. fdy means of the pressureexercised by the annular part of piston l the material is forced upwardin tapering shape. The walls of the mold exercise pressure upon thematerial, imparting to it a high degree of density. The tapering mandrelis caused to take art in the u ward motion, being held fast y theshriniiage of the material while cooling. This reaction, in case themandrel rose in the same degree as the piston I, would cause a splittingof the material as it cooled further; but this accident is prevented bythe retrograde mo- -m encounters the tion of the mandrel imparted by theupper The piston, which as it is smaller than the lower one, is at firstcompelled to rise, but by closthe pressure liquid beci ing up theopening 0 hind piston b is gradually compressed to recede or fall back.the apparatus so as to regulate the motion of the pistons according tothe extent of the shrinking. Fig. 2 shows the press after the completionof the process. lhas traveled the distance p w. The upper piston hastraveled the distance The disk f has been sheared ofi in the motion. Thehollow block 9 is finished. The escape from the tube n, the pistons aand I return to their the upper piston is presse downward, and in itsfurther course the plate finished block and pushes piston b is compelledIt is easy to control The piston pressure fluid is then allowed tooriginal position,

it out.

ically by means of curves. In F difierent blocks.

iston a. urther, 8 denotes and\t the time within which the process iscompleted. It will be seen from the curves without further explanationthat the disretrograde motion.

tance m represents themea the predetermined curves which form thecontrol diagram. the control mustbe conducted, and thus one has at anytime an illustration of the condition of the process.

and the mold the duration of the process can be shortened as much asdesired. The distance t will then be correspondingly reduced.

Having thus described our invention, What we claim is- Process for theproduction of highly-densified hollow metal blocks or ingots whichconsists in casting the metal into a taperin mold around a tapering ofhigher degree, solidify, the taper mold together with the taper mandrelto increase allowing the mandrel to retrograde during the motion,substantially as described and for the purpose set forth.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing winesses motions of the piston aretransferred by ns of a suitable indicating device upon According tothese curves By cooling the mandrel mandrel or core 0 ta er thenallowing the meta to then pressing the ingot axially into the density,

MIL BIER. ADOLF HOFFMANN.

In presence of

